The title \"Sparrow\" is popularly associated with which of the following personalities?

Introduction / Context:
This question is from the area of modern personalities and nicknames or popular titles. Competitive exams frequently ask about epithets associated with important leaders, soldiers and public figures. The title 'Sparrow' is a distinctive nickname, and connecting it to the correct person requires memorising such associations from general knowledge sources.

Given Data / Assumptions:

• We have four personalities: Sardar Vallabhbhai Patel, Rajinder Singh, Nelson Mandela and Porus.
• The question asks specifically about the title 'Sparrow'.
• We assume the standard GK association used in exam question banks.
• Other titles of these personalities (like 'Iron Man' for Patel) must be kept in mind to exclude them.

Concept / Approach:
Sardar Vallabhbhai Patel is famously called the 'Iron Man of India', Nelson Mandela is widely known as the 'Father of the Nation' in South Africa and associated with the struggle against apartheid, while Porus is remembered as an ancient Indian king who fought Alexander. The title 'Sparrow' is not linked to them in conventional GK. In Indian military history and popular references, the nickname 'Sparrow' is associated with Rajinder Singh, known in certain contexts for his bravery. Therefore, among the given options, Rajinder Singh is the personality to whom the title 'Sparrow' is attributed in exam-oriented material.

Step-by-Step Solution:
Step 1: Recall that Sardar Vallabhbhai Patel is commonly titled the 'Iron Man of India', not 'Sparrow'.Step 2: Remember that Nelson Mandela's famous epithets relate to his leadership in South Africa, not to the word 'Sparrow'.Step 3: Note that Porus is known for his battle against Alexander and is not generally called 'Sparrow' in standard GK.Step 4: Recognise that multiple GK question banks link the title 'Sparrow' with Rajinder Singh.Step 5: Select 'Rajinder Singh' as the correct answer.

Verification / Alternative check:
General knowledge compilations and online MCQ resources that list personality titles include entries stating that Rajinder Singh is associated with the nickname 'Sparrow'. While this may not be as universally known as some other titles, it appears consistently in the type of GK sources used for competitive examinations, which makes it the expected answer when this exact question appears.

Why Other Options Are Wrong:
Sardar Vallabhbhai Patel: Correctly known as the 'Iron Man of India'; no standard GK source pairs him with 'Sparrow'.Nelson Mandela: Revered for his anti-apartheid role and called 'Madiba' or 'Father of the Nation' in South Africa, not 'Sparrow'.Porus: An ancient ruler of the Punjab region who fought Alexander; he is not popularly linked with the title 'Sparrow' in exam syllabi.

Common Pitfalls:
Because the title 'Sparrow' is less familiar than more famous epithets like 'Iron Man' or 'Mahatma', some students may try to guess based on prominence and mistakenly pick Patel or Mandela. The safest strategy is to memorise such less-famous but exam-friendly nickname questions from reliable GK lists. When facing similar questions, eliminate options whose well-known titles you already know and then select the remaining option associated with the nickname asked.

Final Answer:
The title \"Sparrow\" is associated with Rajinder Singh.